Apparatus for making multi-layer cream-filled wafer blocks

ABSTRACT

Cream-coated wafer sheets are conveyed by a feeder conveyor in a first plane to a stacking device. The coated wafers are raised in the stacking device into a second plane and by such a raising are attached to the lower sides of a wafer sheet already in the second plane to form a wafer block which is in a raised position with respect to the feeder conveyor. An uncoated covering wafer sheet is separately supplied to each wafer block such that the covering sheet is delivered directly into the second plane at the stacking point, and a coated sheet is attached to the lower side of this covering sheet by raising up into a position in which its cream coating contacts the lower side of the covering sheet. This separate, direct supply of the uncoated covering wafer sheet is effected by a covering sheet conveyor disposed above the feeder conveyor. The terminal end region of the covering sheet conveyor ends in the second plane at the upstream side of the stacking device.

This is a division, of application Ser. No. 274,247, filed June 16,1981, now U.S. Pat. No. 4,391,832.

BACKGROUND OF THE INVENTION

The invention relates to a process for making multi-layer cream-filledwafer blocks.

Wafer blocks are known in the food and biscuits and confectioneryindustry as intermediate products for mechanically produced waferproducts. Among the various known wafer products are cookies andconfectionery, for example, wafer cones, wafer cups, wafer plates, flatwafer discs, hollow croissants, wafer rolls, ice cream cones, filledwafers, ice cream wafers, wafer slices small cream filled wafer bars andthe like. Wafer blocks are also known as a starting product for filledwafers, ice cream wafers, wafer slices small cream filled wafer bars andthe like. All these wafer products are bakery products made from a waferbatter and having a crisp, brittle and easily breakable consistency.

The individual kinds of wafer products differ from one another in thetype of manufacture. Thus, some wafer products are baked in their finalform, as may be the case, for example, with wafer cones, wafer cups,wafer discs and the like. In the case of other wafer products, a wafersheet or an endless wafer strip is first baked; and, in a baked butstill soft state, the wafer sheet or strip is shaped into its finalform. In this form the wafer product cools and assumes its crisp,brittle consistency. Examples of this are ice cream cones, hollowcroissants, wafer rolls and the like.

For wafer products made from wafer blocks, several wafer sheets arebaked, for example, in an automatic baking machine, cooled, coated withcream and formed into a stack. The cream-filled wafer block obtained inthis way is then cut into small handy pieces of equal size. Theresulting product then comes onto the market, packaged in unitsconsisting of one piece or several pieces and, if appropriate, alsopackaged in an air-tight manner. Examples of wafer products of this typeare cream wafer biscuits or cookies.

The various wafer products can be provided with coating such as, forexample, of sugar or chocolate, or can be filled, for example, withedible ice, various creams, chocolate and the like.

Wafers of the present invention may at times be referred to as"waffles", but waffles baked in a waffle iron are to be distinguishedfrom the above-described wafer products. The waffle iron product is asoft baked product analogous to a bread roll or pancake and, therefore,has no similarity at all in its consistency and usability to theabove-described wafer products.

The invention, in particular, relates to a process for makingmulti-layer cream-filled wafer blocks, in which process cream-coatedwafer sheets are conveyed in a first plane to a stacking point, wherethey are raised into a second plane and attached from below to thealready raised part of the wafer block. Each coated wafer sheet is firstpushed under that part of the wafer block which is held in the raisedposition, and then is raised. The wafer block thus formed is removed inthe raised position from the stacking point.

In a certain process of this type, the wafer sheets are conveyed insuccession to the stacking point on a single conveyor belt. On thisconveyor belt, those wafer sheets which are to be provided with creamare coated by the contact coating process, the wafer sheets beingconveyed away, spaced from one another, under a coating head locatedabove the conveyor belt. When a wafer sheet is to remain uncoated, theconveyor belt is lowered, and the wafer sheet runs through under thecoating head without contact therewith and is brought uncoated to thestacking point. Cream-filled wafer blocks can be made in this way if thecream can be applied to the wafer sheets by the contact coating process,since it is possible, in the contact coating process, to convey coatedand uncoated wafer sheets on the same conveyor belt.

There are, however, creams which, because of their consistency, can onlybe applied to the wafer sheets by the film application process, or it isdesirable for other reasons to apply the cream by the film applicationprocess. This may be the case, for example, when a further layer ofcream is to be applied to a first layer of cream. In the filmapplication process, the wafer sheets lying adjacent to one another on aconveyor belt are coated with cream by a film of cream being drawn offcontinuously from a roller by means of a blade and deposited onto thewafer sheets which are guided past underneath the roller by the conveyorbelt. A belt located behind the conveyor belt and running at a higherspeed separates the coated wafer sheets lying adjacent to one another,so that a sufficiently large distance arises between the wafer sheets topermit subsequent stacking. This belt, which runs at a substantiallyhigher speed than the conveyor belt conveying the wafer sheets lyingadjacent to one another under the cream application device, delivers theindividual wafer sheets at intervals to a stacking device.

In the case of wafer sheets coated by the film application process, itis necessary either to deliver the covering sheet separately or to keepa wafer sheet free of cream by other measures.

There is also a process in which each wafer sheet is first raised in thestacking device and, as soon as the next wafer sheet is in positionunder the raised wafer sheet, the raised wafer sheet is allowed to droponto it. In this process, although each wafer sheet is raised to formthe stack, the raised wafer sheets are lowered onto the coated wafersheet lying underneath, and the wafer sheets combined in this way arethen raised again. The covering sheet is then deposited from its ownconveyor belt onto the already assembled wafer block. Since the descentof the already raised wafer sheets before the next raising of the stackrepresents an additional process step, requiring a certain period oftime, the efficiency of this process is limited.

In another apparatus for making cream filled wafer blocks by means of asingle cream application device, the wafer sheets are coated with creamby the contact coating process on a feed belt before entry into astacking device. They are then subsequently introduced into a verticalconveyor which consists of two screw tracks rotating about verticalaxes. Uncoated wafer sheets are obtained by lowering the feed belt,since there is then no contact between the cream application device andthe wafer sheet. However, this is not possible in the film applicationprocess, since the film is, of course, not interrupted by lowering thefeed belt. Consequently, such apparatus cannot be used for making waferblocks consisting of wafer sheets coated by the film applicationprocess.

SUMMARY OF THE INVENTION

The object of the invention is, therefore, to provide a process andapparatus, permitting the formation of blocks and unobstructed dischargeof the complete wafer block even at the highest working speeds and evenin the case of wafer sheets coated by means of a film.

In the process according to the invention, this is achieved by virtue ofthe fact that the covering sheet of the wafer block is delivered to thestacking point separately from the coated wafer sheets. Specifically,the covering sheet is directly deposited in a second plane which is inthe stacking location in which the first coated wafer sheet is attachedfrom below to the covering sheet. The apparatus for carrying out theprocess according to the invention includes a feed belt for the coatedwafer sheets and a take-off belt which is provided, if appropriate, witha calibrating roller for the wafer block. Between the feed belt and thetake-off belt is a vertical stacking device which raises the coatedwafer sheets from a first plane into the second plane. The verticalstacking device has two screw tracks, i.e., helical tracks, lyingopposite one another. These screw tracks are arranged as an extension ofthe feed belt and rotate in opposite directions about vertical axes. Amovable stop is located in the direction of transport immediately behindthe screw tracks. There is a conveyor device for the covering sheet,which conveyor device ends in the second plane before the screw tracks.This covering sheet conveyor is located above the feed belt.

By means of the process according to the invention and the apparatus forcarrying this out, a very precise and rapid formation of a wafer blockfrom wafer sheets coated by the film application process is madepossible while as gentle a treatment as possible for the individualwafer sheets is attained. At the same time, one step of the process,namely the raising of the covering sheet, is saved, in comparison withthe other process for wafer sheets coated by the contact coatingprocess. This is accomplished by supplying the covering sheet in thesecond plane during the stacking of the wafer sheets. A greaterefficiency results from this.

In other words, the process of the invention comprises the steps of:conveying, with a feeder conveyor, cream-coated wafer sheets in a firstplane to a stacking point, the coated sheets having upper and lowersides with the cream coating being on the upper side, the coated sheetsfor any one wafer block including at least a first coated wafer sheetwhich is conveyed to the stacking point prior to any other coated wafersheet; thereafter raising the coated wafer sheet into a second planewhich is above the first plane and, by such raising, attaching thecoated wafer sheet to the lower side of a wafer sheet in the secondplane to form a wafer block which is in a raised position with respectto the feeder conveyor, the attaching being effected by the contact ofthe cream coating of the wafer sheet being raised with the lower side ofan immediately adjoining sheet in the second plane. The process alsoincludes the steps of thereafter removing the wafer block from thestacking point; and separately supplying, prior to the removing step, anuncoated covering wafer sheet for each wafer block, each covering sheethaving an upper and lower side, the supplying being carried out suchthat the covering wafer sheet is delivered directly into the secondplane at the stacking point and the first coated sheet is attached tothe lower side of the covering sheet by raising of the first coatedsheet into a position in which its cream coating contacts the lower sideof the covering sheet which has been delivered into the second plane.

A further feature of the invention provides that the covering sheet issupplied in the second plane simultaneously with the first coated wafersheet of the wafer block, the latter being supplied in the first plane.This measure ensures the saving of a further process step, in comparisonwith the other process, and, consequently, a further increase inefficiency.

In preferred apparatus for carrying out the process according to theinvention, the conveyor device includes a chute which can be blocked bymeans of a movable barrier or the like. Here, it is advantageous for onewafer sheet in the chute to be always prevented by means of the barrierfrom sliding further so that, when a new wafer block is being formed,the barrier needs to be removed from the chute only briefly. Thisenables an uncoated wafer sheet to slide onto the vertical feeders(i.e., screw tracks or helical tracks) of the stacking device to detainthe next wafer sheet sliding along in the chute. This design provides aparticularly simple construction of the apparatus, in which the stackingdevice requires no special devices at all for the uncoated wafer sheet.

In other words, the apparatus of the invention comprises a feederconveyor for moving cream-coated wafer sheets in a downstream directionin a first plane and a stacking device disposed adjacent to andgenerally downstream of the feeder conveyor for receiving cream-coatedwafer sheets from the feeder conveyor and for stacking the wafer sheetsvertically one under the other to form a wafer block, the stackingdevice having an upstream and downstream side. There is also a run-offconveyor disposed downstream of the stacking device for receivingcompleted wafer blocks discharged from the stacking device and fortransporting such wafer blocks away from the stacking device. Thestacking device includes means for: vertically lifting a cream-coatedwafer sheet received from the feeder conveyor above the feeder conveyorand into a second plane which is above the first plane and for attachingthe lifted cream-coated wafer sheet to the lower side of a wafer sheetin the second plane to form a wafer block which is in a raised positionwith respect to the feeder conveyor, the attaching being effected by thecontact of the cream coating of the wafer sheet being raised with thelower side of an immediately adjoining sheet in the second plane. Theapparatus also includes means for controlling discharge of the completedblocks from the stacking device and means for separately supplying anuncoated wafer sheet for each wafer block by delivering the coveringsheet directly into the stacking device in the second plane so that acream-coated wafer sheet is attached to the lower side of the coveringsheet by raising of the coated sheet into a position in which its creamcoating contacts the lower side of the covering sheet. This separatesupplying means includes a covering sheet conveyor for conveying theuncoated covering wafer sheet in a downstream direction. The coveringsheet conveyor has a terminal end region, the covering sheet conveyorbeing disposed above the feeder conveyor with its terminal end regionending in the second plane at the upstream side of the stacking device.

The stacking device includes a pair of vertical feeders for engaging andvertically raising the wafer sheets to effect stacking thereof, thesevertical feeders comprising rotatable helical tracks (i.e., screwtracks) in the form of coiled, rod-like elements, the helical tracksproviding an upward spiral movement, the helical tracks having axes ofrotation. There is also means for rotatably driving the helical tracksin opposite rotary directions relative to one another.

Moreover, a further feature of the invention provides that the barrieris formed by a row of bristles, and a guide plate extending up to therow of bristles, is located in front of (i.e., upstream of) the barrierabove the chute. This makes it possible to gently stop the wafer sheetswhich slide along. Thus, damage to the end edges by the stop isprevented.

Furthermore, according to the invention, the barrier may be embodied bya row of bristles. This barrier passes through the chute from below(i.e., from the lower side to the upper side), and the guide platelocated above is at the shortest distance from the chute in the regionof the row of bristles. In other words, the guide plate is spaced fromthe chute such that the distance between the guide plate and the chuteis different at different points along the chute. This distance is theshortest in the region of the row of bristles.

It is thus possible for the covering sheet to pass partially between theguide plate and the row of bristles and, consequently, to be brakedslowly.

Furthermore, the invention provides that at least the terminal endregion of the chute is arranged parallel to the second plane defined bythe screw tracks. As a result, an especially gentle delivery for thecovering sheet is obtained.

The movable barrier may be formed by a plate which is mounted forpivoting movement about an axis parallel to the chute. The plate restsin the chute and is movable off from the chute.

It is further provided, according to the invention, that the stop, whichis located immediately behind the screw tracks in the direction oftransport, is arranged so that it can be displaced at right angles tothe second plane formed by the screws tracks. In this case, it isadvantageous that the part of the wafer block which has already beenraised into the second plane rests against the stop over its entireheight and, when a new wafer sheet is attached, slides along the stop bymeans of a side face.

The stop is part of a discharge controlling means disposed immediatelydownstream of the stacking device to provide a stop for each wafer sheetto prevent discharge thereof from the stacking device during stacking.This stop also provides an end guide for aligning the wafer sheetsduring stacking, the stop being vertically movable between an upperdischarge blocking position above the run-off conveyor in which thewafer sheets in the stacking device engage the stop, a lower dischargeposition below the second plane in which the wafer sheets in thestacking device do not engage the stop and in which the completed waferblock is free to move downstream, and an intermediate vertical positionabove the second plane and below the main conveying surface of therun-off conveyor in which intermediate position the stop blocksdownstream movement of the covering sheet in the stacking device. Thedischarge controlling means also includes a light gate disposed upstreamof the stacking device for sensing the position of a wafer sheet, thelight gate being operatively coupled with the stop for initiatinglowering thereof, the light gate also being operatively coupled with thedriving means for the helical tracks. The displacement of the stop is atright angles to the second plane.

The apparatus according to the invention is also distinguished by anextremely small space requirement. Thus, the length of a line ofequipment for the production of wafer slices can be reducedconsiderably. In an apparatus according to the invention, the wafersheets can also, if necessary, be coated with cream by the contactcoating process without the advantages of the process according to theinvention being lost as a result.

BRIEF DESCRIPTION OF THE DRAWING

The invention is described in more detail below with reference to anexemplary embodiment illustrated in the drawings for carrying out theprocess according to the invention.

FIG. 1 shows a section through the apparatus according to the inventionalong the line I--I of FIG. 2;

FIG. 2 shows a plan view of the apparatus according to FIG. 1;

FIG. 3 shows a section through the stacking device along the lineIII--III of FIG. 4;

FIG. 4 shows a plan view of the stacking device according to FIG. 3;

FIG. 5 shows a detail of the chute on an enlarged scale; and

FIG. 6 shows a detail of the left-hand portion of an apparatus similarto that of FIG. 7, but wherein a swinging plate barrier is used in placeof a barrier of movable bristles.

DETAILED DESCRIPTION

The apparatus according to the invention consists of a stand 1, in whicha feed belt (i.e., a feeder conveyor) 2, a stacking device 3 and atake-off belt (i.e., a run-off conveyor) 4 are located. The two belts 2,4 each have a frame 5, by means of which they are mounted on thestand 1. A chute 6 for the uncoated wafer covering sheets is mountedabove the feed belt 2. If appropriate, a calibrating roller (not shown)for the wafer block is mounted above the take-off belt 4. The chute 6has a terminal end region 16 which ends above the feed belt immediatelyin front of (i.e., upstream of) the stacking device 3. As will beapparent from the drawing, the terminal end region 16 is adjacent one ofthe ends of the chute; i.e., terminal end region 16 is adjacent theterminal end of the chute. Of course, the terminal end of the chute isthat end which the covering sheet passes when it has traveled along thelength of the chute. Located above the chute 6 is a barrier 9 which canpivot about a horizontal axis and which can be raised from the chute orlowered towards the chute 6. Barrier 9 prevents a covering sheet lyingon the chute from sliding further. The barrier may also be formed by arow of bristles 31 which can be removed from the sliding path of thewafer sheet and which can be raised from the chute at right anglesthereto or lowered towards it. The chute 6 is inclined relative to thehorizontal conveying plane of the feed belt 2 in such a way that, whenthe barrier or the stop is removed, the wafer sheet lying on the slide 6slides along the chute 6 into the stacking device 3 as a result ofgravity alone.

The base of the chute 6 may be provided with longitudinal slits 32, sothat the covering sheet slides only on the webs remaining between thelongitudinal slits. The barrier 9 in the form of a row of bristles canbe located underneath the chute, so that the bristles pass through thebase of the chute from below by way of the longitudinal slits. In theraised state, the bristles stand against a guide plate 30 located abovethe chute 6. The guide plate 30 is inclined towards the chute 6 and isprovided, in the region of the row of bristles, with a curvature leadingaway from the chute 6, so that the distance between the guide plate 30and chute 6 is shortest in the region of the row of bristles.

A covering sheet sliding along the chute 6 to the barrier 9 is detainedvery gently due to the formation of the barrier 9 as a row of bristles.This is because the covering sheet passes partially through between theguide plate 30 and the row of bristles and, in so doing, is braked. Ifthe row of bristles is arranged above the chute 9 so that it can beraised relative to the latter, then the covering sheet is detained bybeing held between the base of the chute 6 and the row of bristles. Themovable barrier may also be formed by a plate 22 which is pivotableabout an axis parallel to the chute 6. (See FIG. 6.) Plate 22 rests onchute 6 and is movable off from chute 6.

The release of the uncoated covering sheet by, for example, lowering therow of bristles or lifting the pivotable plate 22, is controlled via alight barrier 10 located in front of the feed belt 2 and via anadjustable counter on which the number of wafer sheets of a wafer blockcan be set.

A cream application device (not shown) is located in front of the feedbelt 2, in the direction of transport, above a conveyor belt (not shown)which conveys under the cream application device the wafer sheets whichare to be coated and which lie adjacent to one another. In the region ofthe light barrier 10, the foregoing conveyor belt transfers the coatedwafer sheets lying adjacent to one another to the feed belt 2 which runsat a substantially higher speed. As a result of this, the coated wafersheets are separated from one another and are delivered to the stackingdevice 3 singly and spaced from one another. Because of the differencein the speed of conveyance of the coated wafer sheets which are conveyedlying adjacent to one another, on the one hand, and the speed ofconveyance in the stacking device 3, on the other hand, the period oftime necessary for the stacking operation itself is obtained.

The stacking device 3 consists of two screw tracks (i.e., helicaltracks) 11, 11' which adjoin the feed belt 2 in the direction oftransport and lie opposite one another and which can rotate aboutvertical axes and receive the wafer sheets between one another. Thescrew tracks 11, 11' consist of wire-shaped spring steel bent along ahelix, the screw tracks 11, 11' rotating in opposite directions andbeing coiled in a sense opposite to their direction of rotation. In thescrew track 11' on the right, looking in the direction of transport, theturns ascend in a counter-clockwise direction, and the screw track 11'rotates about its vertical axis 12' in a clockwise direction. In theopposite screw track, i.e., screw track 11 on the left, the turn ascendin a clockwise direction. The left screw track 11 rotates in acounter-clockwise direction about an axis 12 parallel to the axis ofrotation 12' of the right screw track 11'. The distance of the screwtracks 11, 11' from the respective axes of rotation 12, 12' correspondsapproximately to half the length of a wafer sheet 7, looking in thedirection of transport. Each of the two screw tracks 11, 11' has onlytwo turns and is fastened, by means of a diametrical arm 29, 29' to ashaft 26, 26' forming the axis of rotation 12, 12'. The arm 29, 29', aswell as half to one turn of each screw track 11, 11', is locatedunderneath the transport plane of the feed belt 2. When the screw tracks11, 11' are stopped, the points where the two screw tracks 11, 11' firstintersect the transport plane of the feed belt 2 are located outside theactual stacking region and substantially in the plane perpendicular tothe transport direction and defined by the axes of rotation 12, 12' ofthe screw tracks 11, 11'. The distance between the axes of rotation 12,12' of the two screw tracks 11, 11' corresponds to the width of onewafer sheet 7, increased by the diameter of one shaft 26. Under theseconditions, an optimum support for the friable and easily breakablewafer sheet 7 is achieved.

The shafts 26, 26' of the screw tracks 11, 11' are mounted, at theirrespective lower ends, in a plate 13, fastened to the stand 1 of theapparatus. Each of the shafts 26, 26' is driven intermittently by itsown motor 14, 14', so that the screw tracks 11, 11' perform only onerevolution each time. The control of the motors 14, 14' and the designof the control are such that each of the screw tracks 11, 11' alwaysstops in one and the same position after one revolution. It is ensured,in this way, that the wafer sheets do not butt against screw tracks 11,11', but enter between them. As a result of driving the screw tracks 11,11' with their own motors 14, 14' respectively, the space above or belowthe stacking device is kept free, so that any wafer blocks in whichdefective wafer sheets have been processed may be removed from theapparatus in a simple way by striking the wafer block with the edge ofthe hand between the screw tracks 11, 11', so that the wafer blockbreaks and falls down out of the stacking device. It is necessary, forthis purpose, that the pitch of the screw tracks 11, 11' correspond to2.5-4 times the thickness of the wire-shaped spring steel constitutingthe screw tracks 11, 11'. In this way, the fragments of the wafer blockdo not become jammed between the turns of the screw tracks. For the samereasons, the width of the wire-shaped spring steel constituting thescrew tracks 11, 11' should also amount only to between one-hundredthand one-twentieth of the mean diameter of the screw tracks 11, 11'.Also, the effective part of the screw tracks 11, 11', that is to say,that part which projects above the transport plane of the feed belt 2,should consist of only one to one and a half turns. The upper end of thescrew tracks 11, 11' is flattened.

To give the screw tracks 11, 11' more support, they are provided, ontheir parts located outside the actual stacking region, with one or moreguides. These may include either of (1) an arcuate slit 27 between walls25 opposite one another, or (2) several bars 28 or rotatably mountedrollers located alternately on the inside and on the outside of thescrew tracks. The wall parts 25 delimiting the slit 27, and the bars 28or rollers can appropriately be applied, separately from one another,against the screw tracks 11, 11'. The motors 14, 14' of the screw tracks11, 11' are switched on by means of the same light barrier 10 which alsocontrols the release of the uncoated wafer covering sheet on the chute6.

The wafer sheets entering from the feed belt 2 between the turns of thescrew tracks 11, 11' are conveyed up from a first plane 33, into whichthey are conveyed from the feed belt, into a second plane 34, from whichthe finished wafer block is discharged by means of the screw tracks 11,11'. The screw tracks 11, 11' rotate in opposite directions and theirturns raise the respective wafer sheets lying on the two screw tracks11, 11' synchronously from the first plane into the second plane. Duringthis process, certain components of forces which are transmitted to thewafer sheet as a result of the rotation of the screw tracks 11, 11'(i.e., forward components which point in the direction of transport)would tend to impart a forward movement of the wafer sheet in thedirection of transport. To prevent this forward movement of theindividual wafer sheets before the wafer block is finished, there islocated immediately behind (i.e., downstream of) the screw tracks 11,11' a stop 21 which consists of several fingers 20 fastened in a plate30 and along which the wafer sheets 7 slide during the time that theyare conveyed up by the screw tracks 11, 11'. Thus, the rotating screwtracks will slide relative to the wafers when the stop is in a blockingposition. When the desired number of wafer sheets, which number has beenset on the counter, has advanced into the stacking device 3, that is tosay, when the last wafer sheet is still located in the first plane ofthe stacking device 3, then, when the first coated wafer sheet of thenext block passes the light barrier 10, the first rotation of the screwtracks 11, 11' is triggered. As a result of this, the last wafer sheetof the block previously formed is attached to the latter from below.After this first revolution has been completed, the stop 21 descends. Atthe same time, the second revolution of the screw tracks 11, 11' isstarted without interruption.

As a result, the wafer block is released and is transferred from thescrew tracks 11, 11' onto the take-off belt 4, during which time thestop 21 returns to its first position in which it remains with its topedge below the transport plane (i.e., the main conveyor surface) of thetake-off belt 4. As soon as the screw tracks 11, 11' come to astandstill after the second revolution, the covering sheet in the chute6 is released and slips onto the screw tracks 11, 11' and, therefore,into the second plane 34. At the same time, the first coated wafer sheetis pushed from the feed belt 2 into the first plane of the screw tracks11, 11'. When the second coated wafer sheet passes the light barrier 10,the stop 21 moves into its upper, second position, and the first coatedwafer sheet is applied from below to the covering sheet by the screwtracks 11, 11'.

The return of the stop 21 to its initial position in two steps isnecessary because, when the finished wafer block is conveyed out of thestacking device 3 by means of the forward force component imparted bythe screw tracks 11, 11', the wafer block is not moved beyond the regionof the stop 21 by the screw tracks. It is only conveyed further by thetake-off belt. Thus, if the stop were to return to its initial positionimmediately, the result would be that the tips of the fingers 20 of thestop 21 would slide along the bottommost wafer sheet of the wafer blockto be discharged and would, in so doing, damage this wafer sheet.

The wafer block is pushed out by means of the screw tracks 11, 11'themselves by means of the auxiliary devices located in the interior ofthe screw tracks 11, 11' and by means of the take-off belt 4. Theauxiliary devices comprise guide rollers 23 which grasp the wafer sheetsor the wafer block at the edges parallel to the conveying direction ofthe belts 2 and 4. The shafts 26, 26' carrying the screw tracks 11, 11'are likewise formed as guide rollers. In this way, it is ensured thatthe finished wafer block has already left the stacking device 3 beforethe covering sheet of the next wafer block is introduced into the secondplane of the stacking device.

The stop 21 is actuated by means of a compressed air cylinder 24 whichengages on the plate 30 and which is likewise controlled by the lightbarrier 10 and the counter.

The guide rollers 23 are driven from the shaft 26 of the screw track 11via V-belts or round belts 17. The guide rollers 23 of the auxiliarydevice are at a standstill when the wafer sheets are introduced. Theseguide rollers also have the function of ensuring that the individualwafer sheets are exactly aligned relative to one another and have thefunction of assisting the stacking device 3 when the wafer block isdischarged from the latter. However, it is possible to have a drive ofthe guide rollers 23, which is independent of the drive of the screwtracks 11, 11'. With such a drive, the guide rollers can assist the feedbelt 2 when the wafer sheet 7 is introduced into the stacking device 3.

The axles of the guide rollers 23 are mounted at their upper end in agallows-like bracket 18. A stripper 19 is assigned to each of the guiderollers 23 and to the shaft 26 carrying the screw track 11 to preventcream issuing from the sides of the wafer block from adhering to theguide roller 23 or to the shaft 26. The screw tracks 11, 11' themselvesrequire no strippers, since they clean themselves automatically as aresult of the relative movement with respect to the wafer sheets. Thetwo guide rollers 23 can also constitute direction-changing rollers fora conveyor belt which fulfills the same functions.

According to a further alternative version of the invention, there canbe provided a fixed second stop parallel to the movable stop.

This second stop projects above the second plane, but its top edge doesnot project above the transport plane of the drive belt 4. This secondstop projects somewhat, with respect to the movable stop, towards thestacking device 3. When the movable stop is lowered below the transportplane of the take-off belt 4 in order to discharge a finished waferblock from the stacking device 3 and after the last coated wafer sheethas been attached to this wafer block, then, during the time that thefinished wafer block is conveyed out of the stacking device 3, thecovering sheet of the next wafer block and at the same time its firstcoated wafer sheet come to rest against the fixed stop. This is so thatthe movable stop can return to its upper end position without, in sodoing, touching the end edges of the first two wafer sheets of the nextwafer block, which are already located in the stacking device 3. Whenthe first coated wafer sheet of the next wafer block is raised by meansof the stacking device 3 out of the first plane into the second planeand is thereby applied from below to the covering sheet already locatedin the second plane, the two wafer sheets slide along the fixed stop andonly come to rest against the movable stop just below the transportplane of the take-off belt. The wafer sheets then slide further up alongthis movable stop while further coated wafer sheets are attached.

The mode of operation of apparatus according to the invention isdescribed in more detail below with reference to the formation of afive-layer wafer block.

The coated wafer sheets are conveyed by a conveyor device (not shown),for example, a conveyor belt of the cream application device, to thelight barrier 10. The uncoated covering sheets arrive, via the chute 6,in front of the barrier 9.

As soon as the first coated wafer sheet of the new wafer block to bemade has passed the light barrier 10 and is transferred to the feed belt2, a signal is triggered at the light barrier 10. This causes, by meansof a control which, if necessary, works with a time delay, a lowering ofthe barrier 9 from the chute 6. This further causes a consequent releaseof a covering sheet and the immediate switching on of the drives of thescrew tracks 11, 11'.

The latter perform one complete revolution, by means of which the lastcoated wafer sheet of the preceding wafer block is raised and is appliedfrom below to the other wafer sheets which are already joined to oneanother. After the screw tracks 11, 11' have performed the one completerevolution, the stop 21 is lowered into its bottommost position, and thedrives of the screw tracks 11, 11' rotate the tracks further through asecond complete revolution. As a result, the preceding finished waferblock is pushed by means of the guide rollers 23 onto the constantlyrunning take-off belt 4 and is conveyed by the latter out of the regionof the screw tracks 11, 11'.

In the meantime, the stop 21 ascends one step. After the second completerevolution of the screw tracks 11, 11', their drives are switched off.Only then is the first coated wafer sheet of the new wafer block pushedby the feed belt 2 into the lower turn of the two screw tracks 11, 11'which has become free. At the same time, with the screw tracks 11, 11'at a standstill, the covering sheet released by the barrier 9 passes viathe chute 6 into the upper turn of the two screw tracks 11, 11' andcomes to rest against the stop 21.

After the preceding wafer block has been discharged by the take-off belt4 and the stop 21 has been raised into its upper end position, and whenthe second coated wafer sheet of the new wafer block to be made passesthe light barrier 10, the screw tracks 11, 11' are made to rotate again.As a result of this, the first coated wafer sheet of the new wafer blockis raised and attached to the covering sheet. After the screw tracks 11,11' have been stopped, the second coated wafer sheet of the wafer blockenters the lower turns of the screw tracks 11, 11'. The second coatedwafer sheet is raised as soon as the third coated wafer sheet passes thelight barrier 10. The latter wafer sheet is attached to that part of thewafer block to be made which is already in the raised position when thefourth and last coated wafer sheet of the wafer block having five wafersheets passes the light barrier 10. This last wafer sheet enters thelower turns of the screw tracks 11, 11' after the latter have beenstopped, and therefore after the third coated wafer sheet has beenattached. As already described, this last wafer sheet is raised when thefirst coated wafer sheet of the next wafer block passes in front of thescrew tracks 11, 11'.

What is claimed is:
 1. An apparatus for manufacturing wafer blockshaving layers of wafer sheets, the wafer sheets having upper and lowersides, the apparatus comprising:a feeder conveyor for movingcream-coated wafer sheets in a downstream direction in a first plane; astacking device disposed adjacent to and generally downstream of saidfeeder conveyor for receiving cream-coated wafer sheets from said feederconveyor and for stacking the wafer sheets vertically one under theother to form a wafer block, said stacking device having an upstream anddownstream side; a run-off conveyor disposed downstream of said stackingdevice for receiving completed wafer blocks discharged from the stackingdevice and for transporting such wafer blocks away from the stackingdevice; said stacking device including means for: vertically lifting acream-coated wafer sheet received from said feeder conveyor above saidfeeder conveyor and into a second plane which is above said first planeand for attaching the lifted cream-coated wafer sheet to the lower sideof a wafer sheet in said second plane to form a wafer block which is ina raised position with respect to the feeder conveyor, said attachingbeing effected by the contact of the cream coating of the wafer sheetbeing raised with the lower side of an immediately adjoining sheet inthe second plane; means for controlling discharge of the completedwaffle blocks from the stacking device; means for separately supplyingan uncoated covering wafer sheet for each wafer block by delivering thecovering sheet directly into said stacking device in said second planeso that a cream-coated wafer sheet is attached to the lower slide of thecovering sheet by raising of the coated sheet into a position in whichits cream coating contacts the lower side of the covering sheet, saidseparate supplying means including a covering sheet conveyor forconveying the uncoated covering wafer sheet in a downstream direction,said covering sheet conveyor having ends, one of which is a terminalend, the terminal end being that end past which the covering sheet moveswhen the covering sheet has traveled along the length of the coveringsheet conveyor, said covering sheet conveyor having a terminal endregion adjacent said terminal end, said covering sheet conveyor beingdisposed above said feeder conveyor with its terminal end region endingin said second plane at said upstream side of said stacking device. 2.An apparatus according to claim 1, wherein said stacking device includesa pair of vertical feeders for engaging and vertically raising the wafersheets to effect stacking thereof, said vertical feeders comprisingrotatable helical tracks in the form of coiled rod-like elements, saidhelical tracks providing an upward spiral movement, said helical trackshaving axes of rotation; andincluding means for rotatably driving saidhelical tracks in opposite rotary directions relative to one another. 3.An apparatus according to claim 2, wherein said covering sheet conveyoris formed by a chute, and wherein said supplying means includes amovable barrier which cooperates with said chute to selectively blocksaid chute.
 4. An apparatus according to claim 3, wherein said barrieris formed by a row of bristles, and wherein said supplying meansincludes a guide plate above said chute on an upstream side of saidbarrier, said guide plate extending up to said row of bristles.
 5. Anapparatus according to claim 4, wherein said chute has a lower sidefacing said feeder conveyor and an upper side facing said guide plate,wherein said barrier passes through said chute from the lower sidethereof to the upper side thereof, and wherein said guide plate isspaced from said chute such that the distance between said guide plateand said chute is different at different points along said chute, saiddistance being the shortest in the region of the row of bristles.
 6. Anapparatus according to claim 3, wherein said second plane is defined bysaid helical tracks and wherein said terminal end region of said chuteis arranged parallel to said second plane.
 7. An apparatus according toclaim 3, wherein said movable barrier is formed by a plate which ismounted for pivoting movement about an axis parallel to said chute,which plate rests on said chute, and which is movable off from saidchute.
 8. An apparatus according to claim 3, wherein said run-offconveyor has a main conveying surface and wherein said dischargecontrolling means includes a stop disposed immediately downstream ofsaid stacking device to provide a stop for each wafer sheet to preventdischarge thereof from said stacking device during stacking, said stopalso providing an end guide for aligning said wafer sheets duringstacking, said stop being vertically movable between an upper dischargeblocking position above said run-off conveyor in which the wafer sheetsin said stacking device engage said stop, a lower discharge positionbelow said second plane in which the wafer sheets in the stacking devicedo not engage the stop and in which the completed wafer block is free tomove downstream, and an intermediate vertical position above said secondplane and below the main conveying surface of said run-off conveyor inwhich intermediate position said stop blocks downstream movement of acovering sheet in the stacking device.
 9. An apparatus according toclaim 8, wherein said discharge controlling means includes a light gatedisposed upstream of said stacking device for sensing the position of awafer sheet, said light gate being operatively coupled with said stopfor initiating lowering thereof, said light gate also being operativelycoupled with said driving means.
 10. An apparatus according to claim 8,wherein said stop is disposed immediately downstream of said helicaltracks and arranged for displacement at right angles to said secondplane.